Office chair



FIG. 1 is a perspective view of the office chair showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. 

CLAIM I claim the ornamental design for an office chair, as shown and described. 